As reported today in Silicon Beat:The VC frenzy over solar company SolFocus; VCs shower it with $32MVCs continue to invest their green in green. The SolFocus investment follows on the heals of the $75 Million Series C funding of Nanosolar in June. Unlike other solar startups developing new and cheaper thin film solar cell/module technologies, SolFocus is developing optics, mirror, passive cooling, and sun tracking technologies to focus the equivalent of 500 suns on high efficiency solar cells. Apparently, SolFocus has partnered with Spectrolab (a Boeing Company) and will probably use Spectrolab’s 28.3% Ultra Triple Junction (UTJ) Solar Cells (or similar), designed for space applications, in the Concentrator PhotoVoltaic (CPV) arrays. SolFocus claims to have developed a low part count, low material cost (glass optics instead of fresnel lenses), and easy to assemble CPV array approach (see presentation) which can drive solar photovoltaics below the $1 per watt price point.

Practical CPV systems face two key challenges. Since CPV systems can only focus direct beam light from the sun, not diffuse light scattered by the atmosphere, they are best used in direct light rich locations. CPV systems must also be pointed at and track the sun, and the tracking mechanisms add to system cost, decrease reliability, and increase maintenance.

Concentrator photovoltaics is not a new idea, and a number of other startup companies are competing with SolFocus to commercialize their concentrator technologies. Concentrix Solar, a Fraunhofer ISE spin-off, is bringing a fresnel lens concentrator product to market about the same time as SolFocus. Concentrix showcased their technology at the Intersolar 2006 tradeshow. Solar*Tec AG (Munich, Germany) and Solaria (Fremont, USA) are two more examples of many competing companies at various stages of concentrator photovoltaics commercialization.